Correction of refractive errors using contact lenses is well known. Conventional contact lenses provide correction for low order optical aberrations, such as defocus and astigmatism, leaving higher order aberrations uncorrected. Recently, contact lenses for correction of higher order aberrations have been disclosed as well. Typically, low and high order ocular aberrations are measured as departures from a spherical wavefront at any position on the wavefront. To correct the aberrations, the geometry of one or more surfaces of the lens is designed to compensate for the departures from the spherical wavefront.
Some individuals have ocular conditions including, without limitation, keratoconus, irregular astigmatism, corneal dystrophies, and ocular trauma that produce more extreme aberrations than in the population at large. Additionally, even for those individuals without such ocular conditions, the compensating geometry necessary for correction may be such that data to describe the entire diameter of the optic zone is not available. Also, one or both of the optic zone and lens edge may have areas of excessive variations in thickness. In each of these scenarios, the variations result in a lens that may be difficult to manufacture and the variations can make the lens uncomfortable on-eye.